The Trump administration took a concrete step Monday toward allowing companies to conduct seismic tests in the search for oil and natural gas off South Carolina’s coast, with the publication of a proposal to allow five companies to use air guns to blast sound waves into the ocean.

The document includes a measurement of the incidental harm the blasts could have on marine life.

The publication, which officially enters the Federal Register on Tuesday, sets off a 30-day comment period before the National Oceanic and Atmospheric Administration issues final approval.

The data collected through seismic testing would be sold to oil and gas companies and would update 30-year-old maps of the ocean’s subfloor to provide companies and the federal government with more information about where oil or gas deposits may be located off the Mid-Atlantic and South-Atlantic coasts, including South Carolina. The mapping information is considered proprietary and wouldn’t be released to the public.

In April, President Donald Trump signed an executive order setting in motion a review of the Obama administration’s decision to close the Atlantic coast from leases for oil exploration. Last month, the Department of Interior announced it would reverse Obama’s denial of permits for seismic testing and begin to review the companies’ applications.

A widespread campaign in opposition of Atlantic oil exploration has taken root in cities and among commercial fisherman and businesses along the length of the East Coast. More than half a million commercial fishing families, 41,000 businesses and 125 local governments along the coast have come out against the proposals, according to Frank Knapp, president and CEO ofBusiness Alliance for Protecting the Atlantic Coast, an advocacy group.

Coastal residents fear the environmental and economic impacts an oil industry would bring to the tourism-rich coast, while industry leaders laud the economic windfall an established offshore industry could add to the state.

If finalized, likely in the next few months, the draft proposal would grant permits to five companies to conduct the testing in waters from three to 350 miles off the coast from the New Jersey/Delaware border to central Florida. Boats tugging giant arrays of air guns pointed at the ocean floor would crisscross the Atlantic, blasting the air in intervals every few seconds across thousands of square miles of ocean.

While still reviewing the 300-page document, environmental groups blasted what they called junk science used to justify seismic testing, a controversial practice shown to cause hearing damage to whales and fish and which environmentalists fear will have a devastating effect on aquatic life in the Atlantic, some of which is in peril.

The Bureau of Ocean Energy Management has set requirements for the testing companies to beware of whales or dolphins swimming in proximity to the air gun arrays. Spotters would watch with binoculars for whales swimming within 500 meters of the sonic arrays.

The draft proposal evaluates each company’s application separately and doesn’t factor in the cumulative effect of multiple tests in the same regions going on simultaneously, said Michael Jazny, director of the Marine Mammal Protection Project at the Natural Resources Defense Council, an environmental advocacy group.

He called that “alternative science” and nonsensical behavior by an agency under pressure from Trump.

“It’s like trying to assess air quality by looking at just what comes out of a single smokestack,” Jazny said. “These surveys will be targeting the same populations of animals.”

Jazny referred to a letter sent to BOEM in 2015 from 75 marine scientists that said air gun testing would cause long-lasting, significant harm to the reproduction and survivability of ocean life in testing areas.

Environmental groups have said the testing could affect the 400 to 500 remaining endangered North Atlantic Right Whales as well as sea turtles, dolphins, commercial fish catches and beaked whales, a species most prominent near Cape Hatteras, North Carolina that is vulnerable to sound and susceptible to stranding.

“This threat is real and it’s coming fast,” said Nancy Pyne, campaign director at Oceana, an international ocean conservation and advocacy organization. “Coastal communities have the most to lose, but unfortunately their overwhelming opposition may be ignored by the Trump administration.

"The threats of seismic air gun blasting alone are bad enough, but it’s also the first step to offshore drilling, which could lead to the industrialization of coastal communities and the risk of another BPDeepwater Horizon-like disaster. The time to protect our coast is now.”

Industry representatives said they welcomed the publication of the proposed Incidental Harassment Authorizations for seismic surveys.

Dustin Van Liew, the government affairs director for the International Association of Geophysical Contractors, said the publication comes nearly two years after the first applications were submitted and will “finally” allow its members to comment on the proposals.

“Tomorrow’s publication is further evidence by the Trump Administration that it is committed to offshore energy development, recognizing the need for new and updated information ... for making informed energy policy decisions about America’s resources on behalf of the American people,” Liew said.

The five companies up for approval are ION Geoventures, Spectrum, TGS-NOPEC Geophysical Company, WesternGeco LLC and CGG. The companies would cover much of the same region using similar technology to create the maps.

Knapp, with the business alliance, referenced Trump’s words last week that he works for the people of Pittsburgh, not Paris, when he announced the U.S. would pull out of the Paris Climate Accord.

“Well, the President also works for the people of Charleston S.C., Virginia Beach, the Outer Banks, Miami Beach and every other community along the Atlantic Coast and not the Paris-based CCG Services that wants to attack our Atlantic with air gun blasting,” Knapp said. “He should put America’s Atlantic Coast first and not the profits of foreign seismic companies and their multi-national big oil clients.”

Industry representatives have said there is no scientific evidence of widespread harm to marine life from seismic testing and that tests have been taking place around the globe for a half-century.